$package('wstuo.sysMge');

/**
 * @author scott
 * @constructor
 * @description 提供Base64的加密解密方法
 * @date 2014-07-19
 * @since version 1.0
 */
wstuo.sysMge.base64Util = function() {
	// private property
	_keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
	
	

	return {
		
		//编码密码，并把编码后的字符保存到隐藏域(realityId)中
		encodePassword:function(id,realityId,hidden){
			
			var _v = $(id).val() || "";
			if(_v.length < 1){
				$(realityId).val('');
			}
			var b=$(hidden).val();
			if(_v!=b||b==''){
				var pwd = wstuo.sysMge.base64Util.encode( $(id).val() );
				$(realityId).val(pwd);
			}
			
		},
		//不让密码存在网页中以其他字符代替
		setingPassword:function(val,id,realityId){
			var _v = val || "";
			$(realityId).val( _v );
			$(id).val(wstuo.sysMge.base64Util.createStr( _v.length ));
		},
		//生成指定长度的掩饰字符
		createStr : function(len) {
			var s = "";
			for ( var i = 0; i < len; i++) {
				s += "*";
			}
			return s;
		},
		
		// public method for encoding
		encode : function(input) {
			var output = "";
			var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
			var i = 0;
			input = wstuo.sysMge.base64Util.utf8_encode(input);
			while (i < input.length) {
				chr1 = input.charCodeAt(i++);
				chr2 = input.charCodeAt(i++);
				chr3 = input.charCodeAt(i++);
				enc1 = chr1 >> 2;
				enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
				enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
				enc4 = chr3 & 63;
				if (isNaN(chr2)) {
					enc3 = enc4 = 64;
				} else if (isNaN(chr3)) {
					enc4 = 64;
				}
				output = output + _keyStr.charAt(enc1) + _keyStr.charAt(enc2)
						+ _keyStr.charAt(enc3) + _keyStr.charAt(enc4);
			}
			return output;
		},
		// public method for decoding
		decode : function(input) {
			var output = "";
			var chr1, chr2, chr3;
			var enc1, enc2, enc3, enc4;
			var i = 0;
			input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
			while (i < input.length) {
				enc1 = _keyStr.indexOf(input.charAt(i++));
				enc2 = _keyStr.indexOf(input.charAt(i++));
				enc3 = _keyStr.indexOf(input.charAt(i++));
				enc4 = _keyStr.indexOf(input.charAt(i++));
				chr1 = (enc1 << 2) | (enc2 >> 4);
				chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
				chr3 = ((enc3 & 3) << 6) | enc4;
				output = output + String.fromCharCode(chr1);
				if (enc3 != 64) {
					output = output + String.fromCharCode(chr2);
				}
				if (enc4 != 64) {
					output = output + String.fromCharCode(chr3);
				}
			}
			output = wstuo.sysMge.base64Util.utf8_decode(output);
			return output;
		},

		// private method for UTF-8 encoding
		utf8_encode : function(string) {
			string = string.replace(/\r\n/g, "\n");
			var utftext = "";
			for ( var n = 0; n < string.length; n++) {
				var c = string.charCodeAt(n);
				if (c < 128) {
					utftext += String.fromCharCode(c);
				} else if ((c > 127) && (c < 2048)) {
					utftext += String.fromCharCode((c >> 6) | 192);
					utftext += String.fromCharCode((c & 63) | 128);
				} else {
					utftext += String.fromCharCode((c >> 12) | 224);
					utftext += String.fromCharCode(((c >> 6) & 63) | 128);
					utftext += String.fromCharCode((c & 63) | 128);
				}

			}
			return utftext;
		},

		// private method for UTF-8 decoding
		utf8_decode : function(utftext) {
			var string = "";
			var i = 0;
			var c = c1 = c2 = 0;
			while (i < utftext.length) {
				c = utftext.charCodeAt(i);
				if (c < 128) {
					string += String.fromCharCode(c);
					i++;
				} else if ((c > 191) && (c < 224)) {
					c2 = utftext.charCodeAt(i + 1);
					string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
					i += 2;
				} else {
					c2 = utftext.charCodeAt(i + 1);
					c3 = utftext.charCodeAt(i + 2);
					string += String.fromCharCode(((c & 15) << 12)
							| ((c2 & 63) << 6) | (c3 & 63));
					i += 3;
				}
			}
			return string;
		}
	}
}();